Currently, Mixmax Undo send is not supported for Outlook-based users. To learn more about the Mixmax integration with Outlook, check out How to use Outlook with Mixmax.
You can enable Undo send in your Mixmax Settings. Click the Mixmax logo in the top right of Gmail to open Settings in the Mixmax Dashboard. Then, under the General tab, scroll until you see Undo send. Click the box next to Enable undo send. You can set your preferences for the amount of time for which you can undo a send, from 2 seconds to 30 seconds.
